The ten biggest lies in audio

Started by Cliff Schecht, November 14, 2009, 03:29:48 AM

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dan5150

I like the original article, and there are some good points/comments raised here. I personally always wondered how in the heck people could replace their power cable to their amp, and claim to notice "the difference". When I saw the first ad for those cables, and the following "reviews" in the guitar magazine, it definitely hit my "WTF? Meter".

The video is interesting as well. Say what you will about those guys, but those are some of the most elaborate and crazy looking turntables I have ever seen. Almost art in of themselves.

JKowalski

I like the wobbly rack of equipment that reduces vibrations  :icon_biggrin:

MovingInSloMo

Quote from: MoltenVoltage on November 15, 2009, 12:55:32 AM
Here's the video for the power cable:
http://www.virtualdynamics.ca/Genesis

Grey fluid is leaking out my ears as I am listening.  I dare you to watch the whole thing.

I need to start making $13,000 guitar effects and advertise in the Robb Report and Cigar Aficianado - oh and airplane magazines - right next to America's Top Ten Steakhouses -- "Ten Best Stompboxes over Ten Grand!"

The new Guitar World sister magazine GUITAR afficinado. I saw the ad in GW, I laughed.

amptramp

1. The cable racket is one of the most pervasive and pernicious in audio.  I am surprised that author did not mention how ineffective gold plating is for the connectors.  It is usually 50 microinches and porous, so the cable becomes the sacrificial anode that corrodes from the inside to protect the gold.  I recall several runs of 2N2222A transistors used on a spacecraft I worked on being rejected for rusting of the kovar leads under the gold.  Silver or tin plating would have been better, although people at the time were spooked by tin whiskers.  Gold also can be soldered but produces intermetallic compounds with solder (called "purple plague" because of its appearance under magnification) that result in unreliable connections.

The phase issue is a non-issue.  The speed of information in a cable is c * velocity factor or about 2/3 * c.  Moving the speaker nearer or farther by 1" has the same effect as adding 89280 inches or 16.9 miles of cable.  The reflections of incident waves made by connecting a 0.1 ohm output impedance amplifier to an 8 ohm speaker through ~30 ohm cable will die out in very short order, much faster than any audio waveform.  The only place I have seen the cable matter is in high-impedance low-voltage inputs such as photovoltaic optical detectors where flexure of the cable mobilized stored charges and caused the cable to behave like an electret microphone.  Needless to say, speaker impedances are not in the 25 megohm region that these sensors operate at.

2. Vacuum tubes distort in a different way due to the fact that they follow a 3/2 power law for gain versus bias voltage (and the signal is superimposed on bias).  Bipolar transistors are exponential with both applied current bias and with temperature, so individual stages must be compensated with feedback against temperature variation.  FETs have a square law variation of gain versus bias, so they are better than bipolar transistors but not as good as tubes.  But the static characteristics are not as important as the large interelectrode capacitance that has a pronounced variation with voltage versus the low and invariant capacitance with tubes.  You can make a good semiconductor amplifier, but there is a valid reason guitarists guard their tube amps jealously.

3. Most CD's sound pretty insipid and lacking in bass, but I am not sure whether this is a problem with mastering or the medium itself.  It was sort of like when cars went from carburetors to fuel injection: they started and ran more smoothly, but the great gobs of power that go with rich mixtures were gone.

4. A/B tests can be corrupted by lack of listening time and lack of material that shows the differences between systems.  Volume matching is also critical, as he states.

5. Many years ago, transient intermodulation (TIM) distortion was introduced as a parameter and test issue in audio to account for the poor audio performance of amplifiers that otherwise had commendable specs.  The culprit was propagation delay time through the amplifier combined with high forward gain (the gain without feedback) that caused a spike to appear in square wave tests that remained until the feedback had time to propagate through the system.  The cure was to reduce stage gains and propagation delays.  Feedback works well, but a poor amplifier can exhibit instability and TIM distortion that does not exist without feedback.  The cure is to design the amplifier so that the feedback works properly, not to eliminate feedback because some bozos couldn't design with it.

6. There is some variation in characteristics of capacitors and speakers for a short time after first use.  But as he says, cables are not in the same category.

7. The writer is correct about biwiring.

8. Power conditioners are usually used to compensate for line voltage variation and are a separate consideration from the usual noise and spike filters.  Generally, there should be enough suppression of line voltage variation effects in the circuitry that this is not needed.  The insidious thing is that the power conditioner has a feedback response with its own bandwidth (usually audio) and stability issues, so if you use one, you have to understand that it may not be as transparent as you would like.

9. I has some scratched CD's (courtesy of my Samoyed - see avatar) that I managed to recover with WD40.  But if a CD works, it doesn't need treatment.

10. Golden ears may exist and there are many individuals like myself who have avoided the loud rock concerts and other things that damage hearing and thus may qualify.  But if someone says they can hear nuances in the music that I can't, that's fine - but I will not spend extra to acquire equipment that will reproduce what I can't hear.  (E.G., my lower hearing cutoff is 35 Hz, so response below that does not interest me.)  All a golden ear can tell me is that if I don't hear something he does, I am not going to buy equipment that reproduces what I can't hear.

MoltenVoltage

Quote from: amptramp on November 17, 2009, 11:49:37 PM
1. The cable racket is one of the most pervasive and pernicious in audio.  I am surprised that author did not mention how ineffective gold plating is for the connectors.  It is usually 50 microinches and porous, so the cable becomes the sacrificial anode that corrodes from the inside to protect the gold.  I recall several runs of 2N2222A transistors used on a spacecraft I worked on being rejected for rusting of the kovar leads under the gold.  Silver or tin plating would have been better, although people at the time were spooked by tin whiskers.  Gold also can be soldered but produces intermetallic compounds with solder (called "purple plague" because of its appearance under magnification) that result in unreliable connections.

The phase issue is a non-issue.  The speed of information in a cable is c * velocity factor or about 2/3 * c.  Moving the speaker nearer or farther by 1" has the same effect as adding 89280 inches or 16.9 miles of cable.  The reflections of incident waves made by connecting a 0.1 ohm output impedance amplifier to an 8 ohm speaker through ~30 ohm cable will die out in very short order, much faster than any audio waveform.  The only place I have seen the cable matter is in high-impedance low-voltage inputs such as photovoltaic optical detectors where flexure of the cable mobilized stored charges and caused the cable to behave like an electret microphone.  Needless to say, speaker impedances are not in the 25 megohm region that these sensors operate at.

2. Vacuum tubes distort in a different way due to the fact that they follow a 3/2 power law for gain versus bias voltage (and the signal is superimposed on bias).  Bipolar transistors are exponential with both applied current bias and with temperature, so individual stages must be compensated with feedback against temperature variation.  FETs have a square law variation of gain versus bias, so they are better than bipolar transistors but not as good as tubes.  But the static characteristics are not as important as the large interelectrode capacitance that has a pronounced variation with voltage versus the low and invariant capacitance with tubes.  You can make a good semiconductor amplifier, but there is a valid reason guitarists guard their tube amps jealously.

3. Most CD's sound pretty insipid and lacking in bass, but I am not sure whether this is a problem with mastering or the medium itself.  It was sort of like when cars went from carburetors to fuel injection: they started and ran more smoothly, but the great gobs of power that go with rich mixtures were gone.

4. A/B tests can be corrupted by lack of listening time and lack of material that shows the differences between systems.  Volume matching is also critical, as he states.

5. Many years ago, transient intermodulation (TIM) distortion was introduced as a parameter and test issue in audio to account for the poor audio performance of amplifiers that otherwise had commendable specs.  The culprit was propagation delay time through the amplifier combined with high forward gain (the gain without feedback) that caused a spike to appear in square wave tests that remained until the feedback had time to propagate through the system.  The cure was to reduce stage gains and propagation delays.  Feedback works well, but a poor amplifier can exhibit instability and TIM distortion that does not exist without feedback.  The cure is to design the amplifier so that the feedback works properly, not to eliminate feedback because some bozos couldn't design with it.

6. There is some variation in characteristics of capacitors and speakers for a short time after first use.  But as he says, cables are not in the same category.

7. The writer is correct about biwiring.

8. Power conditioners are usually used to compensate for line voltage variation and are a separate consideration from the usual noise and spike filters.  Generally, there should be enough suppression of line voltage variation effects in the circuitry that this is not needed.  The insidious thing is that the power conditioner has a feedback response with its own bandwidth (usually audio) and stability issues, so if you use one, you have to understand that it may not be as transparent as you would like.

9. I has some scratched CD's (courtesy of my Samoyed - see avatar) that I managed to recover with WD40.  But if a CD works, it doesn't need treatment.

10. Golden ears may exist and there are many individuals like myself who have avoided the loud rock concerts and other things that damage hearing and thus may qualify.  But if someone says they can hear nuances in the music that I can't, that's fine - but I will not spend extra to acquire equipment that will reproduce what I can't hear.  (E.G., my lower hearing cutoff is 35 Hz, so response below that does not interest me.)  All a golden ear can tell me is that if I don't hear something he does, I am not going to buy equipment that reproduces what I can't hear.

Top notch analysis!
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tempus

Well, this site is turning out to be an endless source of amusement. Turns out those $8300 power cables are cheap compared to the 1m long XLR cables at $10 000. Pull the drop down menu to see those babies.

Nice to see that they also sell acoustic treatment products tailored specifically for the intellectually challenged:

http://virtualdynamics.ca/brass-acoustic-lens

"Designed to give you better, cleaner, over all sound on all frequencies.  With heavy brass made to attract vibrations as well as stepped edges to dissipate the accumulated energies, a few of these devices placed strategically around your sound room are sure to rejuvenate your listening experience."

I had no idea that brass attracted vibrations....
And have you seen these?

http://virtualdynamics.ca/ultra

They even come with a Harmonic Slide for only $300 more than the already low price of $US700!



Jarno

These 10 statements are indeed laughable and they always make for excellent discussions, also on diy audio sites. But what really gets the discussions heated is mentioning of the nonsense of Jack Bybees Quantum Purifiers, 10.0 on the "weird-shit-o-meter".
http://www.bybeetech.com/index.asp

Ibanezfoo

Quote from: Jarno on November 20, 2009, 01:55:45 PM
These 10 statements are indeed laughable and they always make for excellent discussions, also on diy audio sites. But what really gets the discussions heated is mentioning of the nonsense of Jack Bybees Quantum Purifiers, 10.0 on the "weird-sh*t-o-meter".
http://www.bybeetech.com/index.asp

Those look suspiciously like those little magnets you clip on your fuel lines in your car...

wavley

Quote from: Jarno on November 20, 2009, 01:55:45 PM
These 10 statements are indeed laughable and they always make for excellent discussions, also on diy audio sites. But what really gets the discussions heated is mentioning of the nonsense of Jack Bybees Quantum Purifiers, 10.0 on the "weird-sh*t-o-meter".
http://www.bybeetech.com/index.asp

Ok, so I see where he gets the idea for this science, in the amplifiers I build for work we actually DO have a problems with electrons getting lost.  BUT, we are talking about un-packaged indium phosphide transistors on a quartz substrate at cryogenic temperatures.  Our solution is to illuminate them with plain old red LED's.  And we do have really do have REALLY expensive cables, but we are also talking about the fact that they are on network analyzers that cost as much as my house and frequencies that don't even start until 1GHz up to 100 or so GHz. So it's a little bit of a difference.
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trjones1

I love the review of the hour by hour changes in sound on this page: http://www.bybeetech.com/FeaturedProducts.asp as what are essentially glorified RCA jacks get "burnt in." 

Also, the mention of quantum mechanics is a surefire sign of BS in my book (as if any extra indications were needed).

CynicalMan

Quote from: trjones1 on November 20, 2009, 05:17:09 PM
I love the review of the hour by hour changes in sound on this page: http://www.bybeetech.com/FeaturedProducts.asp as what are essentially glorified RCA jacks get "burnt in." 

Also, the mention of quantum mechanics is a surefire sign of BS in my book (as if any extra indications were needed).

www.acousticimaginearing.com

Despite the quantumness this pedal is only somewhat BS. IIRC it uses tunnel diodes for distortion which do get their electrical oddness from quantum mechanical effects. Still, the advertising overemphasizes the quantum part and I'm sure if you go deep enough, all electrical components are affected by quantum mechanics.

Paul Marossy

#51
Preface: I didn't read that article linked. Just making a point here based on a couple of responses I saw.

My ears tell me that vinyl 33 rpm records made and mastered in the peak of that technology, played thru a well designed tube stereo sound way better than what's out there today (ie MP3s, CDs, etc).

I know, I'm hearing a lot of harmonic distortion, blah, blah, blah, but it sure sounded warmer and more dynamic to me. They use way too much compression and make the levels too loud these days. Even stuff mastered and recorded in the early days of CDs generally sound better to me. That's probably because they were still thinking the same as the vinyl days but just using a new medium. And some of the art of recording has been lost by automated programs that do everything for you. I can even think of some albums I heard on vinyl as a kid compared to the same album on CD. They don't have the same depth, sparkle or luster as what the vinyl did.

But, OTOH, people wouldn't be able to have MySpace Music pages and simliar things without the MP3 technology. And an MP3 player is a lot less hassle than the old cassette Walkmans, and it does hold a ton of music.

I have experienced vinyl (33 rpm & 45 rpm), 8-track tapes, cassette tapes, CDs, WAVs, MP3s. There's still nothing that sounds as good to me as an old vinyl album from the 70s that was recorded and mastered well, played thru a good turntable into a tube stereo. I have learned to settle for the technology that is out there today, but I honestly don't think it sounds as good. I especially dislike the movement towards compressing the heck out of everything, throwing dynamic range out the window and making everything so loud.

Shepherd

Quote from: Paul Marossy on November 21, 2009, 10:42:19 AM
My ears tell me that vinyl 33 rpm records made and mastered in the peak of that technology, played thru a well designed tube stereo sound way better than what's out there today (ie MP3s, CDs, etc).

The people older than you might remember how much better mono was.

Paul Marossy

Quote from: Shepherd on November 21, 2009, 08:42:18 PM
Quote from: Paul Marossy on November 21, 2009, 10:42:19 AM
My ears tell me that vinyl 33 rpm records made and mastered in the peak of that technology, played thru a well designed tube stereo sound way better than what's out there today (ie MP3s, CDs, etc).

The people older than you might remember how much better mono was.

Is that a serious statement? I prefer stereo over mono myself.

JKowalski

Quote from: Jarno on November 20, 2009, 01:55:45 PM
These 10 statements are indeed laughable and they always make for excellent discussions, also on diy audio sites. But what really gets the discussions heated is mentioning of the nonsense of Jack Bybees Quantum Purifiers, 10.0 on the "weird-sh*t-o-meter".
http://www.bybeetech.com/index.asp

These guys would make great science fiction TV show writers.

Use as many hi tech words as possible and completely circumvent all notions of science and sanity... Throw in a couple space battles and a creepy alien species trying to kill/enslave all humanity... Gold!   :icon_rolleyes:

Tony Forestiere

QuoteThere's still nothing that sounds as good to me as an old vinyl album from the 70s that was recorded and mastered well, played thru a good turntable into a tube stereo.
In the late 70s, the first Boston album on a Fisher turntable through an old Marantz SS receiver kicked the crap out of the CD I have now. Yeah...I wore the grooves off of that album.
"Duct tape is like the Force. It has a light side and a dark side, and it holds the universe together." Carl Zwanzig
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Paul Marossy

Quote from: Tony Forestiere on November 22, 2009, 12:21:53 PM
QuoteThere's still nothing that sounds as good to me as an old vinyl album from the 70s that was recorded and mastered well, played thru a good turntable into a tube stereo.
In the late 70s, the first Boston album on a Fisher turntable through an old Marantz SS receiver kicked the crap out of the CD I have now. Yeah...I wore the grooves off of that album.

Yeah, great example. That first Boston album on vinyl was THE sound I'm talking about.  :icon_cool:

MoltenVoltage

Quote from: Shepherd on November 21, 2009, 08:42:18 PM
Quote from: Paul Marossy on November 21, 2009, 10:42:19 AM
My ears tell me that vinyl 33 rpm records made and mastered in the peak of that technology, played thru a well designed tube stereo sound way better than what's out there today (ie MP3s, CDs, etc).

The people older than you might remember how much better mono was.

I'm pissed I can't get the White Stripes on 78.
MoltenVoltage.com for PedalSync audio control chips - make programmable and MIDI-controlled analog pedals!

Jarno

Quote from: CynicalMan on November 21, 2009, 09:24:35 AMDespite the quantumness this pedal is only somewhat BS. IIRC it uses tunnel diodes for distortion which do get their electrical oddness from quantum mechanical effects. Still, the advertising overemphasizes the quantum part and I'm sure if you go deep enough, all electrical components are affected by quantum mechanics.

I tried to find them in an appropriate package, but I don't have any luck yet. Curious to try them out in a tubescreamer like circuit. They are germanium based, should be good. Another diode to try is perhaps a VCSEL diode (laserdiode) those have quantum wells in their structure, should be excellent for marketing purposes :-) But, good luck finding them in leaded packages! (although, while I'm typing, I think I've seen some stuffed in a TO-can at work, old stuff too, hmmmm...).

sean k

I think one of the biggest lies in my Audio world is that I know what I'm doing. I really have no idea and I'm sorry about that.

Why my stuff works is a complete mystery to me and if it ever sounds good then it's luck alone and even though the intent to do so may be there I'd be fooling myself if I believed it happened because of some inate, inherent or even inherited talent.

Sorry Guys, if I'm good at anything it's the big mans fault.
Monkey see, monkey do.
Http://artyone.bolgtown.co.nz/